What is infertility?

Infertility is when a couple who have been having vaginal sex without contraception have not been able to become pregnant after one year of trying. Women who are over 35 years old and have not conceived after 6 months of trying are also advised to see their doctor.

Women who can become pregnant but cannot stay pregnant may also be considered to be experiencing infertility.

Infertility can be a result of a problem in any of the steps involved in becoming pregnant. These are:

  • Ovulation - the woman's body must release an egg from one of her ovaries
  • Fertilisation - the egg must travel through the woman's fallopian tubes towards the uterus (womb) and the man's sperm must fertilise the egg on the way. Sperm need to be of adequate number and quality to allow fertilisation.
  • Implantation - the fertilised egg must implant in the lining of the uterus.

How common are infertility problems?

Infertility is relatively common with about 15% of Australian couples experiencing fertility issues. Approximately 1/3 of infertility problems are due to female causes, 1/3 are due to male causes and 1/3rd are due to mixed male and female problems or are unexplained.

Female causes of infertility

Ovulation issues - not releasing an egg from either ovary is the most common reason for female infertility. While there are several causes, the most common are Polycystic Ovarian Syndrome (PCOS) and older female age (>35 years).

Blocked fallopian tubes - this can be due to scar tissue from endometriosis, pelvic inflammatory disease (from an untreated infection such as Chlamydia) or from pelvic surgery for conditions such as appendicitis or ectopic pregnancy.

Structural issues - such as large fibroids within the uterus may prevent a fertilised egg from implanting

Medical conditions - medical conditions, especially autoimmune disease e.g., Systemic Lupus Erythematosis, Thyroid disease and Diabetes which affect the whole body can also affect fertility.

Male causes of infertility

While men make sperm throughout their adult lives, the quality of the sperm diminishes as men age. Environmental and other factors which can affect sperm production such as obesity, smoking, alcohol and drugs also play a large part in male fertility. 

Other male factors which affect fertility include genetic causes, testicular problems such as undescended testes, varicocoeles (varicose veins of the scrotum), testicular torsion (twisting), infection, trauma, anti-sperm antibodies and Erectile Dysfunction (inability to get or keep an erection). 

If a man has had a previous vasectomy, he may have fertility problems after an apparently successful vasectomy-reversal.

For further information on male fertility go to:

Improving your chances of pregnancy


Age is a very important factor in fertility. Women are born with all of their eggs already formed in the ovaries which are released throughout her adult life until menopause. Her eggs age with her and will eventually run out. This is why women usually find it harder to conceive after the age of 35 years. Men also experience a decrease in their sperm quality as they age with higher rates of miscarriage in pregnancies where the male partner is over the age of 45 years.

Where practical, couples should plan to try for a baby when they are younger (generally below the age of 35 years). Some women may consider freezing their eggs if they do not have a partner but this can be costly and is an invasive procedure. For further information on egg freezing:

Timing of sexual intercourse

Having sex every 2-3 days throughout the woman's menstrual cycle, particularly during the week before ovulation increases the likelihood of there being sperm already present in the female reproductive tract when the woman releases an egg from her ovary (ovulates). This will improve the chances of pregnancy.

Lifestyle factors

Both being overweight or underweight can significantly affect fertility. Women who are either overweight or underweight may not ovulate. Women who are overweight have higher risks of miscarriage and pregnancy complications such as high blood pressure and diabetes of pregnancy. Aiming for a Body Mass Index of between BMI 20-25, eating a healthy, balanced diet with folate supplements and taking moderate exercise can improve fertility.

The National Health and Medical Research Council recommends that for women who are pregnant, planning pregnancy or breastfeeding not drinking alcohol is the safest option.

It is also important to be aware that alcohol can reduce fertility in both men and women. Alcohol can greatly increase the time it takes to get pregnant and affect the quality of men's sperm and women's eggs. If you are trying to get pregnant you should consider not drinking alcohol at all ( Recreational drugs, including cocaine, heroin, cannabis and ecstasy, have also been shown to affect male and female fertility and should be avoided.

Investigation of infertility

If a couple have been trying to fall pregnant for more than 12 months without success (6 months if the woman is aged 35 years or older), then starting to investigate fertility is recommended. If there are known fertility problems or risk factors such as undescended testes or endometriosis, irregular or no menstrual cycles or recurrent miscarriage then investigations should not be delayed.

Investigations that can be ordered by a GP or Family Planning doctor include:


  • Hormonal blood tests
  • Trans-vaginal pelvic ultrasound to check for structural problems
  • Specialist ultrasound called a Hysterosalpingo Contrast Sonogram which can check the fallopian tubes
  • It is also a good opportunity to check immunity to Rubella (German Measles) and Varicella (Chicken Pox) as, if not immune, vaccination can be given before pregnancy.


  • Semen Analysis: looking at such factors as semen volume, sperm-count, the shape, form and activity of the sperm.

Further investigations and management would require a referral to a gynaecologist who specialises in infertility.

For more information

The information in this Factsheet has been provided for educational purposes only. Family Planning NSW has taken every care to ensure that the information is accurate and up-to-date at the time of publication. Individuals concerned about any personal reproductive or sexual health issue are encouraged to seek advice and assistance from their health care provider or visit an Family Planning NSW clinic.

Infertility is when a couple who have been having vaginal sex without contraception have not been able to become pregnant after one year of trying.

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